If you need quick response...
take it to an auctioneer! They very well may have an idea. They are very knowlegable on "old" items.
Or, you could take it to an OLD pawn shop and tell them youre not interested in selling,
but info if they have knowledge. You dont want the pawn shop to tell you it aint much of anything, you sell it cheap, and then it be something of value... they turn around and sell for high price. (Dont let them see you be anxious)